This invention relates to a vehicle dynamic characteristic control apparatus for use with an automotive vehicle supported on a pair of front wheels and a pair of rear wheels and, more particularly, to a vehicle dynamic characteristic control apparatus for controlling the vehicle dynamic characteristics based upon various vehicle operating conditions by controlling the steering angle of one of the wheel pairs and the difference of the braking forces applied to the left and right wheels of at least one of the wheel pairs.
For example, Japanese Patent Kokai No. 2-283555 discloses a conventional vehicle dynamic characteristic control apparatus for controlling a vehicle dynamic characteristic to a target value based upon various vehicle operating conditions. The conventional vehicle dynamic characteristic control apparatus is arranged to bring the vehicle dynamic characteristic to the target value by controlling the steering angle of one of the wheel pairs when the vehicle yaw rate or vehicle lateral acceleration is less than a predetermined value and by controlling the braking force difference as well as the steering angle when the vehicle yaw rate or vehicle lateral acceleration exceeds the predetermined value.
Although the conventional vehicle dynamic characteristic control apparatus can decrease the number of times the braking force difference control is required so as to reduce the adverse influence on the braking performance, its usefulness is limited. Since the conventional vehicle dynamic characteristic control apparatus is arranged to initiate the braking force difference control by a deviation of the vehicle dynamic characteristic from its target value, it will make an unnecessary braking force difference control in response to a temporary great deviation which can be reduced only by the steering angle control.